Non-Newtonian colloidal disperse systems comprising solid metal-containing colloidal particles predispersed in a disperse medium of at least one inert organic liquid and a third component selected from the class consisting of organic compounds which are substantially insoluble in said disperse medium are known. See, for example, U.S. Pat. Nos. 3,384,586; 3,453,124; 3,492,231; 4,230,586; and 4,264,363.
Two-component urethane coating systems wherein one component is a polyisocyanate and the other component is a polyol dispersed in solvents which evaporate after application of the coating are known. See, for example, "Polyurethanes: Chemistry and Technology, II. Technology", J. H. Saunders and K. C. Frisch, Interscience Publishers, Library of Congress Catalog Card No. 62-18932, pp. 453-607.
Acidic esters of phosphoric acids are a well known class of organic compounds which are derived from phosphorus containing reactants such as phosphorus pentoxide, phosphorus oxychloride, phosphoric acids, polyphosphoric acids, etc., and an alcoholic or phenolic compound of the type ROH according to known procedures. See, for example, U.S. Pat. No. 3,453,124.
A problem with currently available two-component urethane coating systems is their inability to provide acceptable levels of corrosion resistance for certain applications. It would be advantageous to provide a two-component urethane coating system that provided an enhanced level of corrosion resistance as well as other improvements (improved resistance to flammability, improved adhesion to metal substrates, for example) over those urethane systems currently available.